The controversial atheist and evolutionary scientist said that suicide bombers were the inevitable consequence of "nice Christians" and "nice Muslims", the Telegraph reported.
"It's only a tiny minority of any sect which is ever going to get violent or horrible, there is a sense in which the moderate, nice religious people – nice Christians, nice Muslims – make the world safe for extremists," he said.
The author of The God Delusion (Black Swan) was speaking at the Edinburgh International Book Festival, where he was promoting his memoir, An Appetite for Wonder (Black Swan).
"Because the moderates are so nice we all are brought up with the idea that there's something good about religion faith. That there's something good about bringing children up to have a faith.
"Once you teach people that that's a legitimate reason for believing something then you as it were give a licence to the extremists who say 'my belief is that I'm supposed to be a suicide bomber or I'm supposed to blow up buildings – it's my faith and you can't question that," he said.
Earlier this year Dawkins said that reading fairy tales to children was harmful as it encouraged them to believe in things that are not real.